The major objectives of the project are to determine whether abnormalities in the lipid structure or metabolism exist between normal and neoplastic tissue. The possibilities of regulating lipid metabolism as a means of controlling neoplastic growth are also being assessed. Studies will continue to determine the molecular basis for the observed loss of specific oleate to vaccenate ratios in the hepatoma lipids that characterize the lipid classes of normal liver. Generally, the approach will involve the use of metabolic analogues and specific inhibitors to change the level of oleate and vaccenate. Experiments are also planned to elucidate at the molecular level the early changes that occur in the lipid metabolism of the host animal soon after tumor transplantation. We will seek to determine the origin of the unusual hexadecenoate positional isomers that occur at relatively high levels in the hepatoma, but are virtually absent from normal liver. Lipids from subcellular organelles of hepatoma cells will be analyzed at the molecular species level and compared with the corresponding membrane fractions from normal hepatocytes.